Summary

Our current logic using the Typescript compiler API is:

build mode

1. dts.build: false: basic compiler with createCompilerHost and createProgram
2. dts.build: true: incremental build with project references, using createSolutionBuilderHost and createSolutionBuilder

watch mode

1. dts.build: false: incremental program watcher with createWatchCompilerHost and createWatchProgram
2. dts.build: true: incremental build with project references, using createSolutionBuilderWithWatchHost and createSolutionBuilderWithWatch

In this PR, we add createIncrementalCompilerHost and createIncrementalProgram in build mode to support incremental and deal with projects that with composite: true(incremental: true) and do not to build references dependencies. The watch mode API originally support incremental, so we do not to deal with it in this scenerio.

Our logic is beyond what fork-ts-checker-webpack-plugin do

https://github.com/TypeStrong/fork-ts-checker-webpack-plugin/blob/0fab463b21c6edc4d94834568a3f440241d57887/src/typescript/worker/get-issues-worker.ts#L66-L73

For compiler API that not use SolutionBuilder, it seems the buildinfo not actually takes effect, it just generate buildinfo files. And for tsbuildinfo, due to various issues caused by buildinfo such as remove distPath and monorepo sceniro, we decide to delete buildinfo before generating dts in the next PR which is aligned with Modern.js Module. And our dts processing behaviour such as redirect alias, modify dts extensions and adding banner/footer are also not compatitle with ts cache.

For users who want to keep most align with the default behaviour with tsc in incremetal scenerio, they can enable dts.build: true but I think there's no need to do this if they do not want to build dependencies.

Hopefully there won’t be a day where we switch to using tsc bin files directly, and the ts compiler api will be easier to use with more extensive documentation and able to align related behaviors with tsc more easily.

Related Links

close: #404

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).